Justrite Piggyback Cabinets provide additional safe storage for flammables without taking up valuable floor space. Designed to mount on top of Justrites standard 30- and 45-gallon manual or self-close cabinets, they can also be used singly as a benchtop cabinet or stacked to provide additional storage. Piggyback Cabinets also lend themselves to wall mounting with the purchase of a Wall Hanger Assembly. Piggyback units are not to be used with sliding door cabinets